二冷喷淋强度对连铸坯凝固组织的影响

 推导了连铸过程中二冷喷淋强度与连铸参数之间的关系，比较了喷淋强度对2种断面连铸坯凝固组织的影响。结果表明，喷淋强度能更精确地反映铸坯凝固组织与冷却参数间的关系；铸坯表面的枝晶间距为20 μm左右，而中心区为200～350 μm；距表面相同距离，对角线区的枝晶比横向细小。喷淋强度相近时铸坯的凝固规律为：200 mm×200 mm断面中心区组织较细小，150 mm×150 mm断面近中心区组织较细小。从铸坯表面到中心整体上符合凝固曲线左侧规律，但断面大于200 mm×200 mm的连铸坯，中心和近中心区凝固时符合凝固曲线右侧规律。

Influence of Spraying Intensity on Solidification Structure of Continuous Casting Billet During Secondary Cooling

The relationship between spraying intensity and casting parameters was derived during secondary cooling of continuous casting, and the solidification structures of billets with two different sections were compared under different spraying intensities. The results showed that it was more accurate to express the relationship between solidification structures of billet and cooling parameters by using spraying intensity. Dendrite arm spacing was about 20 μm in the surface of billets and about 200-350 μm in the centre. The dendrites in diagonal area were tinier than those in lateral area at the same distance from surface of billet. Under the similar spraying intensity, the rules of solidification for billets showed that the structures in centre area were tiny for billets with cross-section of 200 mm×200 mm, but tiny structures existed in areas close to centre for billets with cross-section of 150 mm×150 mm. During solidification of billets, the left curve of solidification laws was obeyed basically from surface to center, but it was the right curve for centre area and areas close to centre when the cross-sections of billets were larger than 200 mm×200 mm.